[rhythmbox] audioscrobbler: only send new user requests if cached results have expired

[Jonathan Matthew <jmatthew src gnome org>]

commit d7ac17eb4f33924d711599538f606558307fcfaa
Author: Jamie Nicol <jamie thenicols net>
Date:   Mon Sep 6 14:31:52 2010 +0100

    audioscrobbler: only send new user requests if cached results have expired
    
    in rb_audioscrobbler_user_update, check first if the cached results for
    are still valid before sending new requests.
    
    Different requests have different lifetimes. For now recent artist
    responses are valid for an hour, everything else for 24 hours.
    This can be tweaked once we have a better idea of how well this works.

 plugins/audioscrobbler/rb-audioscrobbler-user.c |   94 +++++++++++++++++++++--
 1 files changed, 88 insertions(+), 6 deletions(-)
---
diff --git a/plugins/audioscrobbler/rb-audioscrobbler-user.c b/plugins/audioscrobbler/rb-audioscrobbler-user.c
index ca2c32c..d8a285b 100644
--- a/plugins/audioscrobbler/rb-audioscrobbler-user.c
+++ b/plugins/audioscrobbler/rb-audioscrobbler-user.c
@@ -39,6 +39,13 @@
 #define USER_PROFILE_IMAGE_SIZE 126
 #define LIST_ITEM_IMAGE_SIZE 34
 
+#define USER_INFO_LIFETIME 86400             /* 24 hours */
+#define RECENT_TRACKS_LIFETIME 3600          /* 1 hour */
+#define TOP_TRACKS_LIFETIME 86400            /* 24 hours */
+#define LOVED_TRACKS_LIFETIME 86400          /* 24 hours */
+#define TOP_ARTISTS_LIFETIME 86400           /* 24 hours */
+#define RECOMMENDED_ARTISTS_LIFETIME 86400   /* 24 hours */
+
 static RBAudioscrobblerUserData *
 rb_audioscrobbler_user_data_copy (RBAudioscrobblerUserData *data)
 {
@@ -145,9 +152,13 @@ static void load_from_cache (RBAudioscrobblerUser *user);
 
 static char * calculate_cached_response_path (RBAudioscrobblerUser *user,
                                               const char *request_name);
+static gboolean is_cached_response_expired (RBAudioscrobblerUser *user,
+                                            const char *request_name,
+                                            long lifetime);
 static void save_response_to_cache (RBAudioscrobblerUser *user,
                                     const char *request_name,
                                     const char *data);
+
 static GPtrArray * parse_track_array (RBAudioscrobblerUser *user, JsonArray *track_array);
 static GPtrArray * parse_artist_array (RBAudioscrobblerUser *user, JsonArray *track_array);
 
@@ -478,12 +489,49 @@ void
 rb_audioscrobbler_user_update (RBAudioscrobblerUser *user)
 {
 	if (user->priv->username != NULL) {
-		request_user_info (user);
-		request_recent_tracks (user, 15);
-		request_top_tracks (user, 15);
-		request_loved_tracks (user, 15);
-		request_top_artists (user, 15);
-		request_recommended_artists (user, 15);
+		/* update if cached data is no longer valid */
+		if (is_cached_response_expired (user, "user_info", USER_INFO_LIFETIME)) {
+			rb_debug ("cached user info response is expired, updating");
+			request_user_info (user);
+		} else {
+			rb_debug ("cached user info response is still valid, not updating");
+		}
+
+		if (is_cached_response_expired (user, "recent_tracks", RECENT_TRACKS_LIFETIME)) {
+			rb_debug ("cached recent tracks response is expired, updating");
+			request_recent_tracks (user, 15);
+		} else {
+			rb_debug ("cached recent tracks response is still valid, not updating");
+		}
+
+		if (is_cached_response_expired (user, "top_tracks", TOP_TRACKS_LIFETIME)) {
+			rb_debug ("cached top tracks response is expired, updating");
+			request_top_tracks (user, 15);
+		} else {
+			rb_debug ("cached top tracks response is still valid, not updating");
+		}
+
+		if (is_cached_response_expired (user, "loved_tracks", LOVED_TRACKS_LIFETIME)) {
+			rb_debug ("cached loved tracks response is expired, updating");
+			request_loved_tracks (user, 15);
+		} else {
+			rb_debug ("cached loved tracks response is still valid, not updating");
+		}
+
+		if (is_cached_response_expired (user, "top_artists", TOP_ARTISTS_LIFETIME)) {
+			rb_debug ("cached top artists response is expired, updating");
+			request_top_artists (user, 15);
+		} else {
+			rb_debug ("cached top artists is still valid, not updating");
+		}
+
+		if (is_cached_response_expired (user, "recommended_artists", RECOMMENDED_ARTISTS_LIFETIME)) {
+			rb_debug ("cached recommended artists response is expired, updating");
+			request_recommended_artists (user, 15);
+		} else {
+			rb_debug ("cached recommended artists response is still valid, not updating");
+		}
+
 	}
 }
 
@@ -547,6 +595,40 @@ calculate_cached_response_path (RBAudioscrobblerUser *user, const char *request_
 	                         NULL);
 }
 
+static gboolean
+is_cached_response_expired (RBAudioscrobblerUser *user,
+                            const char *request_name,
+                            long lifetime)
+{
+	char *response_path;
+	GFile *file;
+	GFileInfo *info;
+
+	response_path = calculate_cached_response_path (user, request_name);
+	file = g_file_new_for_path (response_path);
+	info = g_file_query_info (file,
+	                          G_FILE_ATTRIBUTE_TIME_MODIFIED,
+	                          G_FILE_QUERY_INFO_NONE,
+	                          NULL,
+	                          NULL);
+	g_free (response_path);
+	g_object_unref (file);
+
+	if (info == NULL) {
+		return TRUE;
+	} else {
+		GTimeVal now;
+		GTimeVal modified;
+
+		g_get_current_time (&now);
+		g_file_info_get_modification_time (info, &modified);
+
+		g_object_unref (info);
+
+		return now.tv_sec - modified.tv_sec > lifetime;
+	}
+}
+
 static void
 save_response_to_cache (RBAudioscrobblerUser *user, const char *request_name, const char *data)
 {